Past dust explosions in Maine failed to spark change. Will Searsmont?

On May 15, a routine call about a smoldering fire at the Robbins Lumber pine mill in Searsmont turned deadly when a stream of water aimed at the base of an airtight silo triggered a dust explosion. The blast lifted the silo off its foundation, erupted in a fireball and killed volunteer firefighter Andrew Cross at the scene. Assistant Fire Chief Wayne Woodbury and mill co‑owner Alden Robbins suffered severe burns and died weeks later; about a dozen others were injured.

Investigators said the silo, a used Harvestore installed in 1993, was about one‑fifth full of fine pine dust—roughly 36,000 pounds, nearly four times the state’s reporting threshold for combustible‑dust storage. The water stream acted like a pump, forcing oxygen into the sealed upper vault and agitating dust from the walls into a cloud. When the hot embers met the oxygen‑laden dust, the mixture detonated, and the confined vessel had nowhere to vent the expanding gases.

The incident echoes a similar event nine years earlier at Northeast Agricultural Sales in Detroit, where a foreman’s metal shovel struck an exposed wire inside a fertilizer silo filled with sulfur dust. Three workers, including Anthony Tower, were hurt. Company officials blamed human error for bringing a metal tool into a confined space, while federal OSHA inspectors cited systemic dust‑handling failings and fined the firm $48,000.

Physicists describe a dust explosion as needing five elements: fuel, oxygen, heat, dispersion and confinement. In both cases, the fuel was fine particulate matter, the heat came from an ember or spark, and the confinement came from the sealed silo. The water hose supplied both the dispersion force and an unexpected surge of oxygen, completing the chain.

State officials acknowledge gaps in oversight. Maine’s Bureau of Labor Standards handles safety only for public institutions; private mills fall under federal OSHA, which lacks a single binding rule for combustible dust. After several fatal dust blasts in the mid‑2000s, Congress pressed OSHA to draft a comprehensive standard, but the effort stalled amid industry lobbying and was dropped in 2017. When explosions occur, OSHA must rely on the General Duty Clause—a broad requirement that workplaces be free of recognized hazards—and cites voluntary third‑party guidelines to show a company ignored known risks. Experts call this approach post‑disaster prosecution rather than prevention.

At the state level, officials depend on voluntary safety reviews rather than mandatory inspections. Maine offers free workplace‑safety consultations through the Bureau of Labor Standards, which can identify OSHA violations without issuing fines and temporarily shield a shop from federal review. Records show consultants visited nine sawmills in 2023, one in 2024, four in 2025 and two so far in 2026, but the findings remain confidential, so the public cannot tell whether dust levels were examined.

Maine law requires any private facility storing more than 10,000 pounds of combustible dust to report the hazard to the state and local fire departments. Sixty companies have done so, ranging from aerospace parts makers to milk‑carton recyclers to composting sites. Only four of those are sawmills: Hammond Lumber in Belgrade, Louisiana‑Pacific in New Limerick, PalletOne in Livermore Falls and Woodland Pulp in Baileyville. Robbins Lumber disclosed risks for diesel fuel and sulfuric acid but not for its sawdust silo.

State Fire Marshal Shawn Esler said his office does not have authority to audit private industrial sites for dust hazards. “There are a lot of buildings built in Maine that do not require a permit from our office,” he noted. His only contact with Robbins Lumber was a routine review of the mill’s sprinkler‑system blueprints. With a limited staff, the office cannot inspect every private business or verify hazard documentation. While safety experts recommend red warning placards on airtight silos, Maine’s fire code—based on the 2018 NFPA edition—contains minimal guidance on combustible dust and imposes no labeling requirement.

Esler admitted, “I don’t know that the state understood the severity of combustible dust hazards, including myself.” He added that without reform, experts warn another explosion is only a matter of time.

In the aftermath, a coalition of fire officials, sawmill operators, elected leaders and insurers gathered to discuss responses, but they are waiting for the November elections before deciding on any reforms. Esler explained, “I can’t give you the answers about the solutions that I feel may be warranted without consulting with the next governor.” He expressed skepticism about creating a state‑mandated inventory of private silos, noting his office cannot enter a workplace without statutory authority, a complaint or an invitation.

His team is completing a statewide survey of hazardous firefighting foam—mostly stored in public buildings where his office has more leverage—and has secured public funding to hire a surveyor. He also pointed to progress in equipping volunteer fire departments with mapping software that displays reported hazards en route to calls, though the system depends on companies accurately reporting risks and fire departments entering the data.

The push for change is intensified by an impending workforce collapse in Maine’s fire and emergency services and the pressing need for more training. Until policies are settled, reforms remain under discussion behind closed doors. When asked what he would tell a Maine resident wondering how the state will prevent another Searsmont‑scale blast, Esler’s reply was brief: “Wait and see.”

In a statement posted online after the incident, Robbins Lumber co‑owner Catherine Robbins‑Halsted said, “Our objective is not simply to meet current industry standards, but to exceed them,” and added, “We are committed to learning from this event and to doing everything we can to help prevent anything like this from happening again.”

Other voices echoed the urgency. Jeff Lewis of Cross Insurance, which underwrites many independent lumber mills, observed, “Now it’s on everyone’s front burner.” Guy Colonna, a chemical engineer who helped draft NFPA’s combustible‑dust and confined‑space standards, warned, “It is far from just a sawmill problem,” and hoped that anyone taking his training would walk away with at least that lesson. He noted that although his seminars once drew little interest in Maine, a recent two‑day workshop filled within days and generated a wait list large enough for two additional classes, according to a spokesperson for the Maine Department of Labor. Federal data show more than 200 major combustible‑dust incidents nationwide since 1980, claiming over 100 lives and injuring roughly 700 people.